rear sprocket hole enlargement

[crazeehorse]

i needed to enlarge my center sprocket hole , so i took a peice of 1/8" thick steel plate 10" X 10 ", laid my sprocket on the plate, then drilled through two bolt holes on the sprocket, one on each side, then bolted the sprocket to the plate. i then took a 2 inch electrican's metal hole saw, found the center on the plate(inside the center sprocket hole, carefully drilled my pilot hole in the plate, then the metal holesaw did the work.cleaned up the burr with a steel brush wheel on my bench grinder. it took me all of about 5 mins. the only catch, i allready had the hole saw due to my line of work, if you did,nt have one it might be cheaper to have a machine shop do it.however if you do have access to a 2 inch metal holesaw, a drill, & a peice of steel plate, this is a neat, quick way to modify your rear sprocket, for a cruiser brake application, or the like.

 

[oldmanpaintball]

this will take you 3-4 min.
get yourself a cone stone for your grinder ,clamp down the sprocket with 2 clamps and center the cupstone grind down for 1 min and then turn over for another . easy and it works . just sand it down for a clean look
they look like this
http://www.phoenixabrasives.co.uk/foundry.html

 

[stude13]

i did it with a dremel, it took a taste longer.

 

[crazeehorse]

i like the cone idea, i have a dremel, but never seem to be able to keep the right stones, i use it to sharpen my chainsaw, really nice for that.

 

[houcoogster]

here is a pic of mine, holesaw in a drill press and I went one step further and countersunk the bolt holes, I like like ther smooth look ;-)

http://photobucket.com/houcoogster